Household lamps have been changed from fluorescent lamp tubes with larger volume and higher power consumption to fluorescent light bulbs with a smaller size. In general, the fluorescent light bulbs can overcome the problems of the large volume and high power consumption, yet the brightness is insufficient. To overcome the brightness issue while maintaining the size of the light bulbs that can be plugged into a socket, it is necessary to improve the arrangement and density of the fluorescent lamps.
Although the brightness can be enhanced by the arrangement and density of the fluorescent lamps, yet the power consumption will be increased. Further, people pay more attention to the concept of environmental protection in recent years, efforts and capitals are invested to find substitutes for the conventional illumination equipments of such high power consumption. At present, may manufacturers start developing low-power cold cathode tube lamps with a brightness not less that that of the conventional fluorescent lamps while achieving the power-saving requirement.
With reference to FIG. 1, if a general cold cathode tube lamp is applied in a lamp base, the cold cathode tube lamp is installed with a plurality of cold cathode tubes 11, and a lamp base is disposed at the bottom of the U-shaped cold cathode tube 11 and corresponding to a general socket. Since each U-shaped cold cathode tube 11 of this design must be connected independently with an internal circuit board, therefore the circuits installed in the cold cathode tube lamp are usually too complicated. To overcome the issue of the complicated circuit, another cold cathode tube lamp with continuous bent cold cathode tubes is provided.
With reference to FIG. 2 for a second conventional cold cathode tube lamp, a general cold cathode tube is bent and formed in the conventional cold cathode tube lamp to reduce the number of required circuit contacts while maintaining the illumination area of the cold cathode tube as shown in the figure, and this kind of cold cathode tubes has a plurality of continuous repeatedly-bent bends 12, so that the original number of required cold cathode tubes can be reduced and simplified to a single planar bent cold cathode tube. However, the cold cathode tubes of this design can be in a planar shape only. If such cold cathode tube is installed onto a lamp base, the corresponding lamp base must be in a strip form, and thus the volume of the lamp base may become too large. When the cold cathode tube is in a planar form, the density of the light will be scattered and the illumination will be lowered.
With reference to FIG. 3 for a third conventional cold cathode tube lamp, the conventional cold cathode tube lamp has a positioning base 13, a control circuit board (not shown in the figure) installed therein and having an electrode terminal 14 coupled to the bottom of the positioning base 13 and corresponding to a traditional lamp socket, a plurality of cold cathode tube lamps 15 coupled to the top of the positioning base 13, and each of the cold cathode tube lamps 15 is a lamp tube extended upwardly from the control circuit board and continuously and repeatedly bent, and finally extended downwardly to another electrode terminal of the control circuit board and bent along the external periphery of the top of the positioning base to form an arc structure.
However, this type of conventional cold cathode tube lamps 15 can be only bent along the external periphery of the top of the positioning base into an arc structure. Although it can cover a light emitting angle of 360 degrees, the illumination effect is poor and a raster phenomenon may occur.